What is a common method for protein separation?

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) is a widely used method for the separation of proteins based on their molecular weight. The technique operates by applying an electric field to a gel matrix that contains the protein sample. Proteins are denatured and coated with sodium dodecyl sulfate, which provides them with a uniform negative charge. When the electric field is applied, the proteins migrate through the polyacrylamide gel, with smaller proteins moving faster than larger ones due to less hindrance within the gel matrix. This allows for the effective separation of proteins, facilitating analysis and quantification based on their size.

Other methods listed also serve important roles in protein separation but operate under different principles. Centrifugation separates components based on density rather than molecular weight. Thin-layer chromatography employs a stationary phase and a mobile phase to separate compounds based on their affinity for each phase, which is less common for proteins specifically. Affinity chromatography relies on specific binding interactions to isolate proteins, but it is typically used for purifying a particular target protein rather than separating a mixture based on size. SDS-PAGE is particularly favored in many research and laboratory settings for its effectiveness and simplicity in separating proteins